Age Calculator
An age calculator finds your exact age in years, months, and days by subtracting your date of birth from today's date, accounting for leap years and varying month lengths.
How it works
Age = AsOfDate − BirthDate, decomposed as full years, then full months, then remaining days
- Subtract birth year from current year to get a candidate year count.
- If this year's birthday hasn't occurred yet, subtract 1 year.
- Count full months since the last birthday, then remaining days using the actual length of each month.
Worked example
Born 1990-03-15, as of 2026-07-05: 36 years passed on 2026-03-15; March 15 → June 15 is 3 months; June 15 → July 5 is 20 days. Result: 36 years, 3 months, 20 days.
Data & sources
Last updated:
Frequently asked questions
How is age calculated exactly?
Age is the elapsed time between your date of birth and today. Full years are counted first (a year completes on each birthday), then full months since the last birthday, then remaining days using actual month lengths.
Does the calculator account for leap years?
Yes. The calculation uses real calendar dates, so February 29 and leap-year day counts are handled automatically.
What is my age if I was born on February 29?
Legally, most jurisdictions treat March 1 as the birthday anniversary in non-leap years. This calculator counts the year as complete on March 1 when February 29 doesn't exist.
How many days old am I?
The calculator also shows your total age in days — the exact number of calendar days between your birth date and today.
Can I calculate age at a past or future date?
Yes. Set the "Age as of" field to any date to compute age at that moment, such as a school enrollment cutoff or retirement date.